The investigation is concerned with the psychological and social effects on children of growing up in an environment that includes contact with a parent requiring to be hospitalized for a psychotic illness. These effects will be compared and contrasted with those occurring in children whose parents have been admitted to hospital for a physical illness. Two sets of studies are contemplated: 1) a clinical evaluation of the impact of the psychotic system of ideas and affects on the child and his immediate environment at different stages of his development; and 2) and experimental investigation (cognitive, perceptual, communicative and psychophysical) of possible factors conducing to vulnerability to the psychotic influence.